| In this dissertation, the synthesis of 1-picrylnitroimidazole and its derivatives was investigated in details, including the iodination of imidazole and its derivatives, the condensation of imidazole derivatives with picryl chloride, and the nitration of the derivatives of iodoimidazoles. 1-picryl-4(5)-nitro-5(4)-iodoimidazole was synthesized by three different routes and the mechanism of the reaction of imidazole derivatives with picryl chloride was studied. Meanwhile, the reaction conditions such as temperature, time, materials ratio which affect the reaction were optimized. The materials obtained were characterized by means of nuclear magnetism, mass spectrum and infrared. Three different routes to obtain 1-picryl-4(5)-nitro-5(4)-iodoimidazole was showed as follows:The first route:4(5)-nitroimidazole was the raw material, through iodination with KI/ concHNO3/AcOH at refluxing for 4 h, followed by the condensation with picryl chloride to obtain the goal material.The second route:imdazole was the starting material, which was iodided to produce 4,5-diiodoimidazole with n(imidazole):n(iodine)=1:2, through the condensation with picryl chloride, and then followed by its nitration with fuming nitric acid at 100℃for 4 h.The third route:the goal material was synthesized by the reaction of 4,5-diiodoimidazole in sodium sulfite solution to obtain the 4(5)-iodoimidazole, and then through the condensation with picryl chloride and the nitration with the fuming nitric acid.Besides, a new route was designed to prepare 1-picryl-4(5)-nitroimidazole:the 4(5)-nitroimidazole and TBAB were the raw materials to obtain its salt, follwed by its condensation with picryl chloride. As a result,the yield was increased from 49% to 71%.The synthesis of 1-picryl-2,4,5-triiodoimidazole was studied much. The reaction conditions such as electrophilic reagent, the temperature, the base, the solvent and the catalyzer have been studied, but there was no goal material. The possible causes of the reaction were analyzed. |
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